Oil changes! (Again!)

And here's yet another thread to add to the oil change threads on this forum So I figured I'd change the oil in my newly bought 1995 525i ( 160k miles ) just so I could know for certain what kind of oil I have in there and stuff. So, I live in Georgia. It's (obviously) winter right now, temps between appx 40-70 degrees F. So, what oil would you guys suggest? I've heard these cars like thicker oil. Also I've heard if it has been running on fossil oil, it might not be a good idea to switch to synthetic, even though synthetic is usually better. But I have no idea what's been used in it. Also, I read about flushing the system before you change oil on another thread, but I've never heard of this. Is it a good idea, and how would I go about doing that? Lastly, how much oil should I put in it? Thanks a whole lot everyone

1. Always use fully synthetic. A 5 litre bottle of Mobil1 5w30 costs under $30 at walmart.
2. Read the manual on oil thickness recommendations for the engine of your age. Basically, the higher the numbers, the thicker the oil. The number to the left of the letter "w" refers to the thickness of the oil when it is cold, and the colder your climate, the lower that particular number should be to enable your oil to function normally during cold-start situations.
4. We recently advised a lady from Georgia. I believe 5w30 is the right rating.
5. 5 litres is what you need for the m50. M20 engines need only 4 litres.
6. Engine flushes are generally overrated, but I would still do them at least once on a used car that I've newly purchased. Pour 1 quart of straight diesel into the crankcase with the old oil, run the engine at idle alone for around 15 minutes, no revving or driving, then drain the old oil and diesel and replace with new oil and a new filter.
7. Don't waste time with off the shelf engine flush products. Way too little fluid in the bottle and way way too expensive for even that. Use 1/2 or 1 litre of pump diesel in your crankcase instead.
8. Don't lose any sleep if you don't flush your engine. It may not help all that much, most engines are generally clean if regular oil changes were done throughout its lifetime.
9. Mobil1 sells a fully synthetic oil called mobil1 extended performance oil. It is rated for 15k miles. There is no need to change your filters halfway. I recommend that you use that, and change your oil at 14k. If you do mainly short trips and mainly city driving, its best to change your oil at 13k. Shorter trips generate more impurities etc that longer trips at higher average oil temps would eliminate somehow.
10. Resist the temptation to look into the minutiae about synthetic oils even if you encounter long articles going into details, if you don't have an independent interest in the subject. It will ultimately be a waste of time....we are not dealing racing engines and the like.
11. Resist the temptation to use expensive boutique oils. Again, the benefits are usually purely psychological. You generally cannot go wrong with brand name companies like Shell, Mobil1, LiquiMoly, etc. Don't bother with unknown brands. Don't bother with mineral (i.e. non synthetic) oils. Fully synthetic ones are so cheap and affordable that the point is now totally moot.

Sir, I owe you a tune up list.



rgds,
Roberto

Some amount of experimentation with oil might be useful. You can start with 5w30, 5 or 10w40 and 20w50 (this one after winter), and see which one makes your engine feel strongest. Thicker oils seal against worn piston rings better and the gain in compression greater than the losses in higher fluid friction due to its greater thickness. The manual recommends 20w50 for high mileage engines. Please check and let us know if your engine qualifies, thanks.

Originally Posted by robertobaggio20

Thicker oils seal against worn piston rings better and the gain in compression greater than the losses in higher fluid friction due to its greater thickness. The manual recommends 20w50 for high mileage engines. Please check and let us know if your engine qualifies, thanks.

You keep saying this but please explain to me how it can be true.

The typical car piston has three rings, the two top ones are to maintain compression, the third, BOTTOM ring is an OIL SCRAPER ring designed to keep oil AWAY from the combustion chamber. Only fuel and air come in from the top, so tell me how oil is accumulating on the compression rings enough to foster a sealing effect?

Do you also understand how tight pistons and rings fit? Compression rings are hard spring steel, the three piece oil rings incorporate a spring that pushes two thin rings against the cylinder wall to scrape oil.

Again, please explain to me how thicker oil is affecting combustion.

Thicker oil can help compensate for excessive rod, main, cam bearing clearances.

There are weeks of reading on BITOG about which oil is "correct" for your car.

I change M1 0w-40 every 5000 miles. It is cheap at wally world and it carries BMW's approval.

I agree with the notion of using synthetics from a name brand, changed often. I agree that most of the rest is speculation. Oil related engine failures are almost non existant in maitained, sensibly driven cars, of any kind.

Thanks for the replies guys! I'll probably flush the engine, however I'm worried that I might have some bad internal seals and that getting the gunk out might cause me to start leaking oil. We shall see, I suppose.

Shine a light in the oil cap hole. If there are accumulations of brown jello, do a flush. If not, it is just a waste of money, brought to you by marketing geniuses.

Originally Posted by snowsled7

You keep saying this but please explain to me how it can be true.

The typical car piston has three rings, the two top ones are to maintain compression, the third, BOTTOM ring is an OIL SCRAPER ring designed to keep oil AWAY from the combustion chamber. Only fuel and air come in from the top, so tell me how oil is accumulating on the compression rings enough to foster a sealing effect?

Do you also understand how tight pistons and rings fit? Compression rings are hard spring steel, the three piece oil rings incorporate a spring that pushes two thin rings against the cylinder wall to scrape oil.

Again, please explain to me how thicker oil is affecting combustion.

Thicker oil can help compensate for excessive rod, main, cam bearing clearances.

There are weeks of reading on BITOG about which oil is "correct" for your car.

I change M1 0w-40 every 5000 miles. It is cheap at wally world and it carries BMW's approval.

I agree with the notion of using synthetics from a name brand, changed often. I agree that most of the rest is speculation. Oil related engine failures are almost non existant in maitained, sensibly driven cars, of any kind.

Have you heard of such a thing as worn piston rings ?

Have you heard of the wet test and the dry test ?

Where did they come from ?

Flush the engine. It is fun. The stuff about seals being ruptured etc has been found to be another urban legend, probably emerged from the time when engine oils were of much poorer quality, in the 60s and 70s.

Oh, yea? I read on another website that high mileage vehicles might have so much gunk in them that a flush could cause blockage and decreased oild flow? Ever heard of that?

BITOG is the site for you. As long as there are folks like Roberto running rampant on the intarweb and general car forums like the Fest, you will get as many answers as there are types of oil in the world.
"Always use synthetic" is wrong. It's better for engines, but most likely not ones that have been running on dino oil for a long time. Synthetic might cause seals to leak that dino won't.
OP- this is your time to experiment with oils to find what's best for you (more so your engine though). I recommend you read up a lot on BITOG, consult your manual for correct weight and specs, and begin!
You are also correct- engine flushes can cause ill effects. Take snow's advice and peek in the top of the engine to see evidence of buildup.

Sent from my ADR6410LVW using Bimmer App

Originally Posted by robertobaggio20

Have you heard of such a thing as worn piston rings ?

Have you heard of the wet test and the dry test ?

Where did they come from ?

I am asking you to explain to me how a different viscosity oil can help worn rings. Please try to answer this question rather than use verbage to try and assail my position.

I assume you are refferring to dropping some oil into a cylinder when testing compression. Do YOU understand that you have to add oil like that because THERE ISNT NORMALLY OIL IN CONTACT WITH THE COMPRESSION RINGS. Where you able to better comprehend if I put it in caps?

The "dry" you refer to is the engine normal state, that is, no oil on the compression rings.

If the numbers improve when oil is added, you have proven a ring seal issue exists. Now again explain to me how the oil in the crankcase can improve the compression. It is not where the compression occurs by design.

So instead of the childlike shots, please attempt to explain yourself using the science of engineering and engine design.

Oil viscosity has NO effect on engine compression as you claim. I have explained in detail why that is. I challenge you to support you opinion with some facts. I do not think you understand what you are talking about.

Are you challenging me ?

Can you really handle it ?

Well you havnt answered robert. I'm curious to see this play out.

Originally Posted by Josh429er

Well you havnt answered robert. I'm curious to see this play out.

Please my friend, allow snowy to cogitate first. He has owned more cars than I have birthdays.

Absolutely bobby, YOU SHOW ME, I will suck it up if I am wrong.

All I am trying to do sonny, is get you educated. When you post things like thicker oil viscosity improves compression, you look foolish.

So if your rings and bores are so worn that oil gets into the combustion chamber, pouring molasses oil in there may slow the burn but it doesn't fix the problem. Oil is not supposed to get past the oil control rings.

At any rate, most BMW engines will still have excellent ring seal at his milage. Your comment was relly a non issue from the start. I know you think it made you look well informed though.

Take the other factiod I handed you and, use that in support of your reccomendation of thicker oil. It can help increase oil pressure when bearing clearances grow with age. That one will make you appear as though you DO know what you are talking about.

So I eagerly await your val kilmer, or whatever, you tube video as proof. I m not sure why you have waited so long if you are so sure you are correct I've asked twice already...

At any rate, most BMW engines will still have excellent ring seal at his milage.
+1 I still use full synthetic 5w30 at 185 k miles with no loss of compression
Sent from my Desire HD using Bimmer App

Then shall we start a new thread on this subject ? Do make the first post.

Seems rather pointless to me, you went down for the count in the first round.

Originally Posted by snowsled7

Seems rather pointless to me, you went down for the count in the first round.

I didnt expect you to concede so easily.

C'mon, the audience is waiting, and this is an interesting subject. I want contributions from others as well. Start the new thread. Come i have given you the right of the first post.

bobby, let's review....

You have made false claims more than once. I have called you on it and, given a detailed account of the facts. If you feel the need to subject yourself to further public humiliation, then go ahead, start a thread.

Here is some additional reading for you.

http://www.hastingsmfg.com/Race_Cata..._Functions.pdf

Oil is not the seal that creates compression, it is the machined fit of the piston ring and bore.

Are you beginning to see where your entire premis is flawed yet?

Snowy, it will just be easier for the mods to lock and delete the thread when it decends into verbal $hit as it surely will when you are proven wrong in substance in this issue and you refuse to concede due to your lack of ultimate self confidence, as you have demonstrated so eloquently in the past. You have challenged me, I have accepted, and me asking you to start a new thread is akin to me saying "lets take this outside". If you don't step out, then......res ipsa loquitur.

Unless I see a new thread from you on this subject, this shall be my last response to you here. I couldn't be bothered about your accusations about me and can't be bothered if most believe it - I drive an E34, remember? I only pay attention to a very few member's personal criticisms out of the hundreds who must be on these forums (that would be the padre, bentley's ghost, bmwFF, radian, TTcummins and rick), and you are not on the list. Intelligent enough general readers can draw their own conclusions and those who decide incorrectly are entitled to their consequences one way or the other, and this of course applies to the both of us in equal measure.

It should bother you that most abhor your posts, it really should. It is not because you have risen to a higher level of consciousness, as you so obviously believe but, that you are wrong when using your own deductions. Your plagerism skills though, are well honed but agin you fail to accuratately utilize what you are slowly learning. You also know you have learned a lot from me, regardless of your "list". If I cared about making your list, I wouldn't constantly be trying to set the facts straight after you post I would just allow you ramble incessantly while giving bad advice. Then we could be friends, right

Best of luck, your thread is waiting.

Getting back to what oil - use what ever the handbook says for your temperature conditions, use name brand dino and change it often.

Originally Posted by BMWFatherFigure

Getting back to what oil - use what ever the handbook says for your temperature conditions, use name brand dino and change it often.

Why dino ?